Method of printing envelopes



July 16, 1940. P. H. DURUP El AL METHOD OF PRINTING ENVELOPES Filed July 11, 1939 VIIIIII 7% Y'QYgg afi Patented July 16, 1940 2,208,046

UNiiEh :srn'ras rA'r-siir orrles METHOD OF PRINTING ENVELOPES Paul H. Durup, Wollaston, and John J. ()rmond,

Boston, Mass, assignors to Artographic Incorporated, Boston, Mass, a corporation of Massachusetts Application July 11, 1939, Serial No. 283,778

9 Claims. (Cl. 101-217) I This invention relates to methods of printing Referring in detail to the drawing, one example envelopes, and other multiple sheet subject matof printing means suitable for carrying out our ter, and to a method of printing such subject matmethod has been illustrated in Fig. 1, in which ter from edge to edge. ill indicates a printing roll, ll refers to a transfer In printing envelopes andsimilar subject matroll and i2 denotes an impression roll. Roll ll) 5 ter it has been found desirable to apply printed is provided with a printing plate l3 of some suitsubject matter entirely over the back side of the able type as a gravure or intaglio type, and the envelope or sheet thereby covering it from edge roll is adapted to rotate in a clockwise manner as to edge. It is also required that such an operaviewed in Fig. 1. This roll picks up ink from a tion be carried out at relatively high speeds, as distributing roll 14 deposited thereon by an ink 10 for example 5,000 or moreenvelopes per hour, in roll IS in association with an ink trough conorder for the cost of the printing operations not to Gaining an ink I 7. l8 denotes a doctor blade rebe prohibitive. At such printing speeds, difficulty ceived in bar IQ for removing excess ink from is experienced in holding an envelope or other t e printing plate 13 during rotation thereof. Ac-

15 similar sheet in a registered position with the cording to the usual manner of oifset printing, 15 printing members. Difiiculty is also experienced the ink is pu d fr m r ssed porti ns f in removing the envelope or similar sheet of mathe plate l3 by the resilient blanket 29 of roll H. terial from the printing roll after printing 00- The latter roll rotates in conjunction with roll curs, on account of the ink tendingto stick the 2 nd pp es ink t e Subject atte to be subject matter to the printing member. Both of printed suppo d o i D eSS n'Dlate 2| of roll 20 these difficultiesare due to the fact that it is not f de ed, th ypes of printing p e possible to apply conventional gripping mechaybe e e d 130111 Carrying out our imp anism against the surface of the envelope since method.

. all of the rear face is required to be covered by In employ n t a ov de ed apparat s the printing ink. we make use of certain mechanical features of an 25 It is the chief object of this invention to provide envelope. Env l p s are u y f a rectangular a method of printing envelopes or similar sheets or square Sh pe; and present a front ace and a from edge to edge,with a view to effecting suitrear face. The rear face comprises an arrangeable registration and to'obtaining adequate sep ment of overlapping flaps secured by adhesive.

aration of the envelope from the printing mem- As an example of one flap arrangement we haveil- 30 bers at high speeds. i lustrated in Fig. 2 an envelope 29 which has folded The nature of the invention will be readily unend flaps 30 and 3!. Glued to the end flaps is a derstood from the following description when bottom flap 32 and loosely overlying the end flaps read in connection with the accompanying drawand the bottom flap is a top fiap33. f

5 ing and the novel features will be particularly t Will be Observed that edges 23 0f the en- 36 pointed out in the appended claims. velope 29 are vformed from folding the flaps over In the drawing: on the front face. These edges are of a some- Figure 1 is a diagrammatic view illustrating what rounded character which are never comprinting means employed in carrying out our imp et y C e y printing ink When passed be- 40 proved method. tween the printing rolls. The reason for this is 40 Fig. 2 is a plan View illustrating a method of that the pressure of the rolls is not great enough positioning and advancing an envelope to printto result in the edges 28 becoming pressed into a ing members. sharply formed line. However, when viewed the Fig. 3 is a detail view illustrating a step of regenvelope appears to be completely covered from istering an envelope between printing members. edge to edge and those portions of the rounded 5 Fig. 4 is a cross section taken on the line 4-4 edges not covered with ink are not observed. of Fig. 2. We make use of this condition, in printing an Fig. 5 is a fragmentary View in end elevation of envelope from edge to edge, to secure registration printing members illustrating separation of an with theelimination of smurring or undesirable envelope from the rolls. v picking up of ink by register mechanism. 50

Our invention comprises an improved method In printing from edge to edge, a difficult type of of printing envelopes at high speed and in the registration is required to be carried out. The absence of gripper mechanism. This application usual registration consists in providing subject is a continuation in part of our co-pending applimatter in a squarely presented position and incation, Ser. No. 251,192, filed January 16, 1939. suring that printing occurs at the same point for 55 each impression. Registration for printing from edge to edge consists in positioning the subject matter not only in a squarely presented position but also in a position such that the edge of the printing plate carrying the printing ink will coincide with an edge of the subject matter. To effect this, some type of guide must be employed and it is customary to employ aguide which is depressed at the nip of the rolls but which provides a surface for receiving an edge of the subject matter up until the point of nip has been reached. When an edge of the ink image is in a position to roll into contact with an edge of the subject matter, it has heretofore been considered practically impossible to prevent ink being picked up by the edge of the depressible guide member against which the edge of the subject matter rests.

Since, by the folding referred to, there is a very small part of an envelope edge which will not receive ink'in any event, we allow the edge to be received against a depressible guide 38 which has been slightly spaced away from the pressure plate 2| of roll l2 as may be more clearly seenin Fig. 4. As a result a substantial bleeding-off operation is effected. By bleeding-off is meant that the subject matter is printed from edge to edge. No smurring of ink occurs due to the slight spacing .described and a high speed, practical, and continuous bleeding-off is made-possible.

It will be observed, as seen in Fig. 5, that an envelope'presents two layers of paper 34 and 35, of which only the top layer receives ink when the envelope is printed. It will also be observed that there is a space between the two layers which is constantly maintained, thereby developing a springiness or a tendency of the two layers to remain apart even after being pinched together. The reason for this springiness is readily ap parent since folded over parts which make up the back of the envelope tend to open up and oc our in a slightly arched state, as illustrated in Fig. 5, while the front of the envelope tends to remain in substantially fiat state. It has been found that this envelope construction, which is common to a majority of envelopes, develops a resistance which may be used to advantage in opposing andlminimizing sticking of the envelope to the printing member. This results in making possible a higher speed operation than would be possible with a single ply sheet.

The tendency of the two plies of paper to spring apart tends to result in there occurring a distortion of the top ply'34 by the printing member after passing the nip of the printing member with the pressure plate member as has been illustrated in Fig. 6. The bottom ply 35 of the envelope tends to pass along in a straight line as has been illustrated and thereby may tend to pull the top ply away from the printing member.

In addition, the mechanical construction of the envelope is such that it may be more effectively utilized by specific positioning to further assist in separating the envelope from the printing member after printinghas occurred. It is pointed out that an envelope may be advanced to the printing members with either the bottom flap 32, end flaps 3B or 31, or top flap 33 in a forward position. Varying amounts of stiffness will be presented by advancing the top flap of the envelope to the rolls first. The reason for this is that the two edges 36 and 31' of the bottom flap 32 are secured by gum or other adhesive which tends to increase stiffness in the envelope. In

addition, the edges converge toward the top flap 33. Therefore positioning of the envelope with the gummed edges 36 and 31 inthis converged position with respect to a printing roll results in the envelope ofiering greatest initial resistance to bending and having the strongest tendency to maintain itself in a flat state, and break away from the inky printing surface.

There are further advantages in presenting the top flap of an envelope in a forward position. This location insures the top flap 33 being completely flattened down when printing occurs, eliminates danger of an unprinted margin developing around the edge of the flap. Also, in this position the printing ink is rolled against those edges where the bottom flap 32 laps over the end flaps 30 and 3|. This results in the ink film tending to effect a sealing action along these edges and also tending to prevent accidental loosening of the edges which may occur when the envelope is exposed to dampness or other unfavorable conditions.

It will be observed that by our method of printing an envelope, it is possible to carry out bleeding-off operation at high rates of speed. In practice, applicants have succeeded in printing as many as 10,000 envelopes per hour by employing the steps above outlined. It will be noted that the elimination of difiiculties arising from ink smurring heretofore encountered have been overcome, a fine character of printing is available, and a sufficiently high-speed operation is possible to effect material savings in the cost of printing envelopes.

While we have thus described a preferred embodiment of our invention, it will be noted that the invention may be employed in other forms without departing from the spirit thereof.

We claim:

1. In a printing'process, the steps which comprise advancing subject matter comprising a plurality of sheets joined together along anedge thereof to printing means, transferring an image from said printing means to one of said sheets, distorting said printed sheet in a direction toward the printing surface by adherence of said sheet to said surface, and separating said sheet from said surface by a pull exerted along said connected edge from another constituent sheet of said subject matter.

2. The process of printing a multiple layer,

sheet having folded edges which comprises advancing the sheet to printing members, printing thereon and then effecting separation of the multiple sheet from the printing member by the pull exerted from the folded edges of the multiple sheet.

3. In a printing process, the steps which comprise advancing resilient multi-ply subject matter to a curved printing surface, transferring an image from said printing surface to one ply of said subject matter, resisting the tendency of said printed ply to adhere to said printing surface, and separating said subject matter from said surface, by the inherent resiliency of said subject matter.

4. In a printing process, the steps which comprise advancing resilient multi-ply subject matter to a curved printing surface, constituent plies of said subject matter being connected at edges thereof but inherently spaced apart intermediate said connected edges, transferring an image from said printing surface to one ply of said subject matter, resisting the tendency of said printed ply to-adhere to said printing surface and separating said subject matter from said surface, by the inherent resiliency of said subject matter, the resiliency of the unprinted ply exerting on the printed ply, through an attached edge thereof, a pull to assist in separating said ply from the printing surface.

5. That improvement in methods of printing a sheet of subject matter between a printing roll and a pressure roll which consists in registering a front edge of said sheet against a depressible guide in one of the rolls, engaging said front edge flatly against the roll while the guide is being depressed, and then passing the sheet between the rolls independently of any holding means on the printing couple.

6. That improvement in methods of printing envelopes between a printing roll carrying a printing image and a pressure roll having a pressure plate thereon, which consists in registering a forward edge of an envelope against a depressible guide in a slightly overhanging position with relation to the edge of the said pressure plate, then engaging said forward edge of the envelope at the nip of the printing image on the printing roll with the forward edge of the pressure plate, and then applying a printing image to the envelope.

'7. That improvement in methods of printing which consists in advancing subject matter toward rolls and against a depressible guide in one of said rolls, holding the forward edge of the subject matter flatly against the depress-ible guide roll and then engaging said front edge of the subject matter with the front edge of a printing image on one of the rolls at the point of nip thereof with the other of the said rolls.

8. That improvement in methods of printing a sheet of subject matter between a printing roll having a printing image on a pressure roll which consists in registering the said sheet against a moving guide in the pressure roll and then engaging the front edge of said sheet with the front edge of a printing image on a printing roll at the point of nip thereof with the pressure roll, and then printing the said sheet from edge to edge independently of any holding means on the printing couple.

9. That improvement in methods of printing a sheet between a printing roll carrying a printing image and a pressure roll having a pressure plate thereon which consists in registering the front edge of the sheet against a depressible guide located adjacent the said pressure plate, then engaging the said front edge of the sheet at the nip of the front edge of the printing image on the printing roll with the forward edge of the pressure plate and then applying a printing image to the sheet.

PAUL H. DURUP. JOHN J. ORMOND. 

